S.G.
I went thru the same thing with my son. He is now almost 5 yrs old. What I did was work with the teachers at his daycare to keep things as consistent at home as at school. This will pass and your grand daughter will develop great social skills and learn so much. I still have trouble on Monday's because he enjoys the weekends so much being at home and all of the attention not to mention he has all of his things around him.
Best of luck